Ball-point writing instrument



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M. S. BAKER BALI.. POINT WRITING INSTRUMENT Dec. 23, 1952 2 SHEETS-SHEET 2 Filed Aug. 17, 1945 mw mw Nw Patented Dec. 23, 1952 UNITED STATES PATENT OFFICE Marlin S. Baker, Janesville, Wis., assgnor to The Parker Pen Company, Janesville, Wis., a corporation of Wisconsin Application August 17, 1946, Serial No. 691,198

3 Claims.

This invention relates to ball-point writing instruments and has to do particularly with devices of that character having a projecting and retracting mechanism operated by a push button for alternately moving the writing point between an exposed, writing position and a concealed, non-writing position.

An object of the present invention is to provide a ball-point writing instrument having an improved push button operated projecting and retracting mechanism.

Another object of the invention is to provide a ball-point writing instrument having a push button operated projecting and retra'cting mechanism which operates upon successive full depressions of the push button to propel the writing point into exposed writing position projecting from the barrel and to retract the writing point into concealed, non-writing ,position within the barrel, respectively.

Another object of the invention is to provide a ball-point writing instrument having a projecting and retracting mechanism actuated by a manually depressible push button which normally projects to a substantial extent from the casing of the instrument, whereby it is readily accessible for manual operation and which after ea-ch depressi-on and subsequent release returns to its initial position.

Another object of the invention is to provide a ball-point writing instrument having a push button actuated projecting and retracting mechanism and wherein the ink reservoir may be remov-ed and replaced by another reservoir by a simple manual operation which may be -performed readily by the user and without requiring the Iuse of any tools.

A further object of the invention is to provide a simple and reliable projecting and retracting mechanism for a ball-point writing instrument which mechanism may be readily manufactured and assembled, which operates positively to project and retract the writing point upon successive depressions of a push button, and which will operate satisfactorily for a long period of use.

Further and more speciiic objects of the invention are to provide an improved ball-point writing instrument having a spring latch for holding the writing point in projected position and a .push button actuated release element for releasing the latch to permit the writing point to be returned to retracted position; to provide an improved projecting and retracting mechanism for a ball-point writing instrument having a latch for holding the writing point in projected posi-tion and a latch (Cl. 1Z0-42.03)

release element yfor rendering the latch ineffective and maintaining it ineiective 4during retraction movement of the writing point; to provide a ballpoint pen having an improved projecting and retracting mechanism wherein the writing point is projected and retracted only upon successive full depressions respectively of a push button, whereby such mechanism is not subject to accidental actuation when the push button is struck or partially depressed; to provide a ball-point writing instrument having an improved projecting and retracting mechanism with means for releasably holding the writing point in projected position against the action of means tending to urge the .point toward retracted position and wherein a rotatable cam is actuated upon successive depressions of a push button to alternately move the writing point to projected position and to release the holding means to permit the point to be returned to retracted position; and to provide a ball-point writing instrument having an improved projecting and retracting mechanism actuated by a depressble push button extending from the b-arrel of the instrument to project and retract the writing point, which push button upon release after being depressed to project the writing point is free to return to its initial extending position independently of .the writing point leaving the latter in projected position.

Other objects and advantages of the invention will appear from .the following description taken in connection with the appended drawings, wherein:

Figure 1 is an elevational view of a preferred embodiment of the invention showing the writing point in propelled position projecting from the casing or barrel;

Fig. 2 is a view of a longitudinal section taken through the casing of the structure of Fig. 1 and showing the internal members there-of in elevation;

Fig. 3 is a view of a longitudinal sectional view taken through the structure of Fig. 1, certain of the internal members being shown in section and others in elevation;

Fig. 4 is a transverse sectional view taken along the line 4 4 of Fig. 3;

Fig. 5 is a transverse sectional view taken along the line 5 5 of Fig. 3;

Fig. 6 is a longitudinal sectional view through the writing instrument of Fig. l and showing the .point-and-cartridge unit in retracted position, with' the Writing point retracted within the casing;

Fig. 7 is a transverse sectional view taken along the line 1 1 of Fig. 6;

Fig. 8 is a fragmentary, longitudinal sectional view through the rearward portion of the instrument and showing the point-and-cartridge unit and project and retract mechanism in their respective positions after the push button has been depressed to propel the unit;

Fig. 9 is a transverse sectional view taken along the line 9 9 of Fig. 8;

Fig. 10 is a view similar to Fig. 8 only showing the members in their positions after the push button has been released and has returned to its rearward position;

Fig. 1l is a transverse sectional View taken along the line of Fig. 10;

Fig. 12 is a view similar to Fig. 8 only showing the members in their positions with the push button depressed to release the latch which holds the unit in projected position;

Fig. v13 is a transverse sectional view takenv alongthe line -I3-i3 4vof Fig.'12; and

Fig. 14 is a diagrammatic view showing the outer surface of the plunger of the projecting and retracting mechanism. in developed form and illustrating particularly the Ashape of the cam track.,

Referring now particularyl to Fig. 2 of the drawings,V the preferred embodiment of the invention includes a barrel or casing'l which, for convenience -in assemblying `the instrument may be formed lby a plurality of sections, such as, a taperedrfront sectionfor tip2, a main section 3, and a rear or end piece 4, joined respectively by threaded connections and 6. The barrel is formed with a bore dening a chamber 1 which accommodates at least a portion of a point-andcartridgey unit 8 and a propel-repel mechanism, hereinafter more fully described.

The pcint-and-cartridge unit 8 includes an ink reservoir sectionl having a reservoir containing a quantity of ink suitable for use with a ballpoint vwriting element, which ink customarily is of a thick, viscous nature. The reservoir section ||J may serve to denne the reservoir, or the latter may itself be defined by a reservoir-forming memberfnot shown) such as a flexible ink-containing sacdisposed within the reservoir section. A ball writing point `is carried at the forward end of the unit 8 and vmounted firmly in a suitable seat L (not shown) for relatively free rotation therein. An ink feed section |2A including a feed channel (not shown) connects the ink reservoir in ink feeding relation with the writing point I Preferably, the ink in Vthe reservoir is maintained under a continuous, vslight pressure tending to urge it from the reservoir and toward the writing point so as to insure the maintenance of a continuous column of ink extending from the reservoir to the writing point.l This may be accomplished in any one of several known ways. For example, Where the reservoir is formed by the reservoir section I0 itself, pressure means suchias a follower (not shown) may be employed. Where a ilexible sac (not shown) is employed, the sac itself may be caused to apply vpressure to theink.

Forwardly of the chamber 1 is a bore--|5 of ref duced diameter which'receives and .guides the reservoir section of the unit 8 and a still smaller boresl which receives and guides Ythe forward, reduced feed section l2.VV

The point-and-cartridge unit 8 ismovable in the barrel for longitudinal shift or projection or retraction movement between a projected po;

sition (Figs. 1, 2 and 3) wherein the writing point projects beyond the forward end of the barrel l and is exposed for writing and a retracted, non-writing position (Fig. 6) wherein the writing point is concealed within the barrel In accordance with my invention a projecting and retracting mechanism is provided for projecting and retracting the point-andcartridge unit 8 in response to successive manipulations of a depressible push button 21. The unit 8 is constantly urged resiliently towards its retracted position and, upon a first depression of the push button 21 is moved into projected writing position and held therein with the writing point projecting from the barrel Upon a second depression of the push button 21 the unit 8 is released and permitted to return to its retracted position with the point concealed with- 1n.

The point-and-cartridge unit 8 is constantly urged toward its retracted position by means which in the preferred embodiment of the invention includes a coil spring 28 (Fig. 3) seated against a suitable shoulder 2| in the barrel and bearing against a flange 22 formed on the unit 8. The shoulder 2| may be formed by the rearward end of the front section 2 as illustrated.y

The unit 8 is adapted to be propelled by a plunger 25 slidably and rotatably mounted in the-v rearward end of the chamber 1 and adapted to be moved into abutment at its forward end with an annular shoulder 26 formed on the unit 8. The plunger 25 is driven by the push button 21 having at least a portion 28 projecting through an opening 29 in the rear end of the barrel I and formed with a flange which is adapted to abut against a shoulder 8| to retain the push button 21 in the barrel The push button 21 preferably is formed with a semi-spherical forward projection 32 seated in a complementary depression 33 in the rear end of the plunger 25 and providing a relatively low friction thrust bearing between the push button 21 and the plunger 25.

Interposed between the rearward end of the unit 8 and the plunger 25, and preferably received and housed in a forwardly open chamber or re'- portion 38 at all times and constantly urges the plunger 25 rearwardly, thus comprising means f for returning the plunger 25 to the rearward position when the manual pressure on the push button 21 is released after each depression thereof.

A spring latch 40 having a dog 39 is rigidly secured in the barrel in position for the dog 39 to engage' the shoulder 26 over a portion only of the periphery thereof when the unit 8 is moved into its projected position, thereby to hold the unit 8 in` projected position. While the spring latch 48 may be secured in the barrel in any desired manner, preferably it is formed integrally with a cylindrical bushing 4|V telescopically received in the chamber 1 and secured therein as by a flange 42 clamped between the forward end of the rear section 4 and a shoulder 43 on the main section 3. The unit`8 is formed with 'a tapered, preferably conical, face 44forwardly of the flange 26 which f permits the latch dog 39 to ride up thereon and over the periphery of the shoulder 26 when the unit 8 is moved forwardly to advance the shoul der 26 past the latch dog 36.

The plunger is provided at its forward end with a projection or latch release element 45 adapted to engage the shoulder 26 of the unit 8 to propel the unit 3 upon depression of the plunger 25 when the unit 8 is in retracted position. The latch release element 45 extends for a portion only of the periphery of theplunger 25. Thus, when the plunger 25 is in a position of angular adjustment wherein the latch release element 45 is aligned with the spring latch 40, the latch release element 45 is adapted to ride under the latch upon forward movement of the plunger 25 and move the latch dog 39 out of engagement with the shoulder 26. On the other hand, when the plunger 25 is rotated to a position wherein the latch release element 45 is not in alignment with the latch 40, the latter can engage the shoulder 26 without interference from the latch release element even when the forward end of the latter is engaged with the shoulder 26. The latch release element 45 thus propels the unit 8 upon a first depression of the plunger 25 and releases the latch 46 upon the next depression.

For the purpose of rotating the plunger 25 to bring the latch release element 45 into position to engage the latch 40, cam means are provided between the barrel I and the plunger 25. Such cam means includes a stud or projection 46 rigidly Secured in the barrel I and riding in a cam track 41 (see especially Fig. 3) which takes the form of a groove in the periphery of the plunger 25. The stud 46 may be integral with the bushing 4I or may be formed as a separate pin extending through the bushing 4I and having a head 48 in the slot 49 provided in the barrel section 3 to admit the head 48.

The cam track 41 which is shown diagrammatically in developed form in Fig. 14 extends completely around the periphery of the plunger 25 and includes four arcuate sections a, b, c and d, respectively, which are alternately inclined in opposite directions. The sections a, b, c and d are so formed and located that, upon a rst manual depression of the push button 21 and consequent forward movement of the plunger 25, the cam action provided by the cam track 41 an-d the stud 46 causes the plunger 25 to be rotated approximately 90. When the manual pressure on the push button 21 is released and the spring 35 returns the plunger 25 to its rearward position, the plunger 25 is rotated approximately 90 further. Upon a Second depression of the bush button 21, the plunger 25 is rotated approximately another 90 and upon its return is further rotated to its initial position. Thus, during a complete cycle of operation of the plunger 25 consisting of two forward and two return strokes, the plunger 25 is rotated progressively in steps of approximately 90 each through one complete revolution about the axis of the casing I. For convenience in illustration, the positions of the stud 46 relative to the plunger 25 at the ends of the several strokes are designated in Fig. 14 as Pos. 1, Pos. 2, Pos. 3" and Pos. 4, respectively.

The instrument during periods of non-writing normally will be maintained with the unit 8 in retracted position (Fig. 6) wherein the writing point II is retracted within the barrel I. writing point II thus is housed and concealed and there is no likelihood of ink soiling the hands Thev or clothes of the user. Moreover, the writing point is fully protected and hence neither the point nor the seat are subject to damage such as may occur if the instrument is dropped when the point is exposed.

If, when the unit 8 is in retracted position (Fig. 6), it is desired to propel the unit 8, the push button 21 is fully depressed. The plunger 25 is driven forward and, since the latch release element 45 is then in engagement with the shoulder 26 of the unit 8, the latter is propelled toward its forward or projected position when the plunger 2'5 is moved into its forwardmost 'position (Fig. 8). The shoulder 26 is advanced slightly beyond the latch dog 39 and the latter rides up on the inclined face 44 and then springs inwardly to engage behind the shoulder 26 to hold the unit 8 in projected position. During this forward movement of the plunger 25, the stud 46 rides along the cam track section a from Pos. l to Pos. 2 (Figure 14) and the plunger 25 is rotated to move the latch release element 45 angularly through into a position where it is out of alignment with the latch 46. Thus the latter is free to engage the shoulder 26 and latch the unit 8 in projected position. When the plunger 25 reaches the end of its forward movement (Fig. 8) the end of the track section a (Fig. 14) abuts against the stud 46 and thus halts further forward movement of the plunger 25. During the forward movement of the unit 8, the ball writing point II moves into its position wherein it projects from the forward end of the casing I and is exposed for writing. The unit 8 is positively and firmly held in projected position by the latch 46 and is not displaced when writing pressure is applied to the writing point II.

When the plunger 25 is in position with the latch release element 45 abutting the shoulder 25 (as in Fig. 6), the plunger spring 35 is compressed. Accordingly, when the manual pressure on the push button 21 thereafter is released, the plunger spring 35 extends and urges the plunger 25 toward its rearward position (Fig 10). The unit 8 remains latched in its projected position but, since the plunger 25 is not attached to the unit 8, the plunger 25 is free to move rearwardly independently of the unit 8. The plunger 25 is urged rearwardly by its spring 35 until the flange 30 of the push button 21 abuts the shoulder 3| and the portion 26 is projected from the casing I and is fully exposed as in the position (Fig. 6) it assumed prior to depression. The push button 21 hence is readily accessible for a second manual depression. During rearward movement of the plunger 2'5, the stud 46 rides along the track section b (Fig. 14) to rotate the plunger 25 through an angle of 90. The track sections a and b are so formed adjacent their junction that when the plunger 25 is released for return movement the stud 46 cannot return to the section a but rides down into the section b and thus continued rotation of the plunger 25 in a single direction isinsured and the plunger cannot reverse its direction of rotation.

When it is desired to retract the writing point I I, the push button 21 is depressed a second time in a manner identical to the first depression and the plunger 25 is driven forward toward the propelled unit 8. The stud 46 rides in the track section c (Fig. 14) and causes the plunger 25 to be rotated to a position wherein the latch release element 45 is aligned with and engages under the latch 40 (Fig. 12). As the plunger 25 approaches the end of its forward stroke, the

mengsel' 2U. halted when the latter is advanced to a position whereinlthe stud reaches Pos. 4(Fig. 14)

..When` the manual pressure on the pushwbutton. 27`is" released the unit 8 is driven rearwardly by` the' main spring. 20 and the plunger. 25 isfdriven rearwardlyby'th'e plunger spring However, the latch release element d5 remains in engagement 'with the shoulder.. ZEduring at least the.

initial ,portion vof 'its' movement and at least Yuntil the'sh'older 26 is moved .rearwardly of andcleas thela'th, thus preventing re-.engagement of the latch andthe'shoulder 2S duing.the're' tting movement of the unit.

35s0` that Vthe shoulder 26 isl held .against the latch release elementd at least during the initial -'return movement of the unit 8. While the plunger sp-ring 3'5 is effective to return the plunge;` whenever the push button 2 is released, the unit' bearing against the plunger 25 vand actuated bythe main spring 2U may aid in moving the plunger 25 rearwardly when the latch-.4 0 is` released. The main spring. 2G is of sufficient strength to return the unit 8 to fully retracted position (Fig. '6) and to maintain it in such position ,against the compressionr of the plunger spring Q35. v

The writing instrument in accordance with the "present invention is so constructed that the unit'8 may be removed'readily. from the casing. Thu`s, when the ink is consumed in writing and thereseirvoir lil is'emptied, the unit 8 may be removed and replaced by a similar unit having affull reservoir. Also, it may be desirable1 in some cases, to replace the unit prior .to exhaustionY of the inl: as, for example, if the ball seat should `become suiiiciently worn' to impair-the good writing qualities of the instrument. To remove the unit 8, it is only necessaryto unscrew and separate the tip 2 and main section 3 .and withdraw the unit it is notnecessary to re;

move the plunger 25 or the members associated therewith and the only element of the projecting andA retracting mechanism which need be removed is the main spring 2G. The plunger 25 andA members associated therewith also may be removed from the'casing if fcrany reason this `is desired as, for example, to permit repair or ad-v justn'ient. This may be accomplished 4by iinscrewing the rear section 4 and withdrawing the However,

a 'simple and eilective mechanism for projecting.. and retracting the Writing point, whereby it may be projected from the casing for writing and retracted within the casingvduring periods vof nonwriting by a simple push button operation. The unit is positively projected into writing position. by'a full depression of the pushbutton and the push button is fully returned after release to its Inthis connec-f tion it will `be understood that the main spring .20. issufliciently stronger. than the plunger spring venient manual manipulation.- -The un itengag es the. plunger during. retraction., m0vement...and hence 'the .Operator by, gradually, .releasing .the

manualpressure on. the push button; can maintain the yunit V under control and prevent a snap action returnof theunit.- g

The unit vis projected bya first full depression of the push .button andgisretracted by. a second. fulldepression of the pushbutton,.consequently there is no likelihood of unintentional actuation of the mechanism as, for example, if the push. button is accidentally struck and partially de-` pressed. 1.Moreover, regardless of the position of the unit, a fulldepressionof. the pushvbutton will alwaysresult in amovement of theunitto its other. position, and hence no particular -sln'll is required to obtain the desired position of the unit.

Iclaim: I 1.- A ball-point writing instrument comprising a 'barrel, a point-and-cartridge including an vink reservoir, a ballwritingelement, and inlc feed means'connecting said re servoir and said writing element, said unit being mountedfor proj jection and retraction moyement in saidjbarrel between avprojected positionwherein said Writing"' eler nent is exposed for writing land `a. retracted position wherein the Writing .ele-

ment Iis concealed within said.barrel spring means resiliently .urgingfsaid unit toward. re tracted position, aspring latch forlatching said unit in projected position when .moved thereto, means including 4a latch release .elementrotatab1e-- and slidable in the barrel, means including a push button .forsliding ysaidlatch release elementand g projectingsaid unit, and cam means. inter-actingr between said latch release element and barrel for. rotating the latch releaserelement in .response to sliding movementsI thereof,. said.latch-r release elementbeing rotatable, progressively in steps,in

a single direction about., the axis of saidsbarrell upon successive depressions of said push button and alternatelyl disengagng said latchfrom said unit topermitsaidunitto be ,retracted by said resilient means and freeing 'saidlatchtopermit thelatter to= engage and lock said unit in projected position. f 2. In a ball-point writing instrument; a casing, a unit. includinganhi'nk cartridge, Ia ball writing ingsaid unit toward retracted positiony latch f' means engageablewith said shoulder .throughout-1 a rst portion only thereof and releasably-holdf ingsaid. unit in projected position-and actuating l' means for said unit and lincludinga-depressible plungerA slidably and rotatably mounted insaid casing.I and .having a projection -extending forwardly therefrom andV-engageable with a second portion only of said shoulder `when propelling saidunitand a pair of cooperating cam elements respectively carried by said casing and plunger and 'imparting funidirectional rotation to said plunger andits `projec'ztion upon successive depressions.. of said plunger, whereby upon a rst depression of .'saidplunger' saidprojection engages said shoulder at said second portion thereof and propels said unit into position wherein said latch means engages said shoulder at said first porti-on thereof and upon a second depression of said plunger said projection is moved into position engaging said shoulder at said rst 'portion thereby engaging said latch means and Inov- :lng said. latch means out of engagement with said. shoulder and said spring means returns said unit to retracted position.

3. The invention as set forth in claim 2 wherein all portions of the shoulder on the unit lie substantially in a common plane transverse to the casing, and the latch means is xed lon.;- tud'inally of the casing.

MARLIN S. BAKER.

REFERENCES CITED The following references are of record in the le of this patent:

Number Number UNITED STATES PATENTS Name Date Moore Apr. 16, 1946 Biro May 21, 1946 Randolph Sept. 9, 1947 Randolph Sept. 9, 1947 Moore May 11, 1948 FOREIGN PATENTS Country Date Germany Apr. 2, 1895 France 1922 Great Britain 1929 Germany 1935 

